Configuring One-Arm BFD for E2E SR-MPLS TE LSP

One-arm BFD for E2E SR-MPLS TE LSP quickly detects faults on inter-AS E2E SR-MPLS TE LSPs and protects traffic on E2E SR-MPLS TE LSPs.

Usage Scenario

One-arm BFD monitors inter-AS E2E SR-MPLS TE LSPs. If a specified transit node on a tunnel fails, traffic is switched to the hot-standby LSP, which reduces the impact on services.

With one-arm BFD for E2E SR-MPLS TE LSP enabled, if the reflector can successfully iterate packets to the E2E SR-MPLS TE LSP using the IP address of the initiator, the reflector forwards the packets through the E2E SR-MPLS TESR-MPLS TE Otherwise, the reflector forwards the packets over IP routes.

Pre-configuration Tasks

Before configuring one-arm BFD for E2E SR-MPLS TE LSP, configure an inter-AS E2E SR-MPLS TE tunnel.

Procedure

Enable global BFD.
1. Run system-view
  The system view is displayed.
2. Run bfd
  BFD is enabled.
3. Run commit
  The configuration is committed.
Enable the ingress to dynamically create a one-arm BFD session to monitor E2E SR-MPLS TE LSPs.
1. Run system-view
  The system view is displayed.
2. Run interface tunnel interface-number
  The view of the E2E SR-MPLS TE tunnel interface is displayed.
3. Run mpls te bfd enable one-arm-echo [ primary ]
  Automatic creation of a one-arm BFD session to monitor E2E SR-MPLS TE LSPs is triggered.
4. Run mpls te reverse-lsp binding-sid label label-value
  A binding SID is specified for a reverse LSP in the E2E SR-MPLS TE tunnel.
  
  Ensure that the mpls te binding-sid label label-value command has been run on the ingress of the reverse LSP.
5. Run commit
  The configuration is committed.
(Optional) Adjust BFD parameters on the ingress.
Adjust BFD parameters on the ingress in either of the following modes:
- Adjust BFD parameters globally. This method is used when BFD parameters for most E2E SR-MPLS TE tunnels need to be adjusted on the ingress.
- Adjust BFD parameters on a specific tunnel interface. If an E2E SR-MPLS TE tunnel interface needs BFD parameters different from the globally configured ones, adjust BFD parameters on the specific tunnel interface.
In one-arm BFD for E2E SR-MPLS TE mode, BFD does not need to be enabled on the peer, and the min-tx-interval tx-interval parameter of the local end does not take effect. Therefore, the actual detection period of the ingress equals the configured interval at which BFD packets are received on the ingress multiplied by the detection multiplier configured on the ingress.

Run the following commands as needed.
- Adjust BFD parameters globally.
  - Run system-view
    
    The system view is displayed.
  - Run mpls
    
    The MPLS view is displayed.
  - Run mpls te bfd { min-rx-interval rx-interval | detect-multiplier multiplier } ^*
    
    BFD parameters are set.
  - Run commit
    
    The configuration is committed.
- Adjust BFD parameters on a specific tunnel interface.
  - Run system-view
    
    The system view is displayed.
  - Run interface tunnel interface-number
    
    The tunnel interface view is displayed.
  - Run mpls te bfd { min-rx-interval rx-interval | detect-multiplier multiplier } ^*
    
    BFD parameters are set.
  - Run commit
    
    The configuration is committed.

Verifying the Configuration of One-arm BFD for E2E SR-MPLS TE LSP

After successfully configuring one-arm BFD for E2E SR-MPLS TE LSP, verify the configurations.

Run the display bfd session dynamic [ verbose ] command to check information about BFD sessions on the ingress.
Run the following commands to check BFD statistics:
- Run the display bfd statistics command to check all BFD statistics.
- Run the display bfd statistics session dynamic command to check statistics about dynamic BFD sessions.